ABB REC670 Bay Control IED

Product Overview

The ABB REC670 is a professional-grade Bay Control Unit (BCU) belonging to the Relion® 670 series. It is designed for the comprehensive control, protection, and monitoring of various bay types within power transmission and distribution networks. Engineered for high-reliability requirements, the REC670 is suitable for all voltage levels, from medium voltage to the highest extra-high voltage (EHV) levels. 

Current Transformer (CT) Interface Data

The REC670 is designed to interface with high-precision Current Transformers to ensure accurate sensing and protection performance under both normal and fault conditions.

• 2000/1 A CT Configuration: This setup is used for high-current measurements with a ratio of 2000 primary amps to 1 secondary amp. It features a Class 5P20 accuracy rating with a 20 VA burden and a secondary resistance of 6.2 ohms. The cable loop resistance must be kept below 0.8 ohms at 75°C (typically less than 100 meters of 2.5mm² cable).

• 100/5 A CT Configuration: This setup is intended for lower-current measurements with a ratio of 100 primary amps to 5 secondary amps. It features a Class 5P20 accuracy rating with a 10 VA burden and a secondary resistance of 0.26 ohms. The cable loop resistance must be kept below 0.4 ohms at 75°C (typically less than 50 meters of 2.5mm² cable).

• Fault Current Handling: For both CT types, the unit is rated to handle a maximum fault current of 40 kA, limited by the switchgear's rated fault capacity.

• Measurement Integrity: Cable loop resistance is strictly limited to minimize voltage drops and prevent CT saturation, ensuring the IED receives a true representation of the primary current during faults.

Application & Engineering Highlights

• Universal Switchgear Control: It supports all common busbar arrangements, including single busbar, double busbar, and one-and-a-half breaker schemes.

• Interlocking and Logic: Advanced programmable logic allows for complex interlocking schemes, ensuring that switching operations are performed safely and correctly.

• High Earth-Fault Current: In cases where high earth-fault currents are expected, the use of two-way cabling may be necessary to maintain measurement accuracy.

• Reactor Inrush Management: The maximum through-fault current is often limited by reactor reactance, with typical inrush currents residing around 800 A.

• Communication Standards: Fully compliant with IEC 61850 standards, enabling seamless integration into Substation Automation Systems via GOOSE messaging and MMS.